BRAND NAMES
 MECHANISM OF ACTION
Benazepril is an ACE inhibitor (Angiotensin Converting Enzyme Inhibitor). ACE inhibitors acts by:
- Inhibiting the formation of angiotensin II from the inactive angiotensin I. Angiotensin II is a potent vasoconstrictor that leads to increased blood pressure.
- ACE catalyses the breakdown of bradykinin (a powerful vasodilator). Therefore, ACE inhibitors, by inhibiting bradykinin metabolism, increase bradykinin levels, which can contribute to the vasodilator activity
- Angiotensin II promotes aldosterone release which normally acts to retain sodium and water, therefore ACE inhibitors promote renal excretion of sodium and water (natriuretic and diuretic effects) by blocking angiotensin II stimulation of aldosterone secretion.
Benazepril is almost completely converted to the active metabolite, Benazeprilat by hepatic cleavage of the ester group, which has much greater ACE inhibitory activity than benazepril
- Treatment of hypertension, alone or in combination with thiazide diuretics (Benazepril/Hydrochlorothiazide)
- Hypertension: The recommended initial dose in patients not on diuretics is 10 mg once daily. Dosage should be adjusted according to blood pressure response. The usual maintenance dosage range is 20-40 mg per day administered as a single dose or in two equally divided doses
- Hypersensitivity to Benazepril or to any other ACE inhibitor
- Patients with a history of angioedema related or non-related to previous treatment with an angiotensin converting enzyme inhibitor.
- Coadministration of aliskiren in patients with diabetes.
- Pregnancy and lactation
 WARNINGS AND PRECAUTIONS
Angioedema: Angioedema has been reported in patients with ACE inhibitors, including Benazepril. Angioedema associated with laryngeal involvement may be fatal. If laryngeal stridor or angioedema of the face, tongue, or glottis occurs, Benazepril should be discontinued immediately, the patient treated appropriately in accordance with accepted medical care, and carefully observed until the swelling disappears. In instances where swelling is confined to the face and lips, the condition generally resolves without treatment, although antihistamines may be useful in relieving symptoms. Where there is involvement of tongue, glottis or larynx, likely to cause airway obstruction, appropriate therapy (including, but not limited to 0.3 to 0.5 mL of subcutaneous epinephrine solution 1:1000) should be administered promptly.
The incidence of angioedema during ACE inhibitor therapy has been reported to be higher in black patients of African heritage than in non-black patients.
- Patients on diuretics may experience an excessive reduction of blood pressure.
- Potassium-sparing diuretics (spironolactone, triamterene, or amiloride) or potassium supplements may have an additive effect on potassium retention, resulting in hyperkalemia.
- Concomitant administration of ACE inhibitors and antidiabetic medicines (insulins, oral hypoglycemic agents) may cause rarely an increased blood glucose-lowering effect with risk of hypoglycemia.
- Caution is advised if non steroidal antiinflammatory drugs NSAIDs are prescribed with ACE inhibitors. (Concomitant use of NSAIDS may result in decreased ACE inhibitor effectiveness). In some patients with compromised renal function who are being treated with NSAIDS, the co-administration of ACE inhibitors may result in further deterioration of renal function. Cases of acute renal failure, usually reversible, have also been reported.
- Lithium carbonate toxicity has been reported when used in combination with ACE inhibitors. If a diuretic is also used, the risk of lithium toxicity may be increased.
- Aliskiren: There is evidence that co-administration of ACE inhibitors, including Benazepril, or of angiotensin receptor antagonists (ARBs) with aliskiren increases the risk of hypotension, syncope, stroke, hyperkalemia and deterioration of renal function, including renal failure, in patients with diabetes mellitus (type 1 or type 2) and/or moderate to severe renal impairment (GFR<60ml/min/1.73m2). Therefore, the use of Benazepril in combination with aliskiren-containing drugs is contraindicated in these patients.
 PREGNANCY AND LACTATION
- Pregnancy Category D (US). ACE inhibitors can cause fetal and neonatal morbidity and mortality when administered to pregnant women (espacially in the second and third trimester of pregnancy). When pregnancy is detected, Benazepril should be discontinued as soon as possible.
- Minimal amounts of unchanged benazepril and of benazeprilat are excreted into the breast milk of lactating women treated with benazepril. A newborn child ingesting entirely breast milk would receive less than 0.1% of the mg/kg maternal dose of benazepril and benazeprilat.
 SIDE EFFECTS
ACE inhibitors are usually well tolerated. Possible side effects include: Dry irritant cough attributable to accumulation of bradykinin, dizziness, somnolence, hypotension (especially during the first days of therapy), fatigue and headache.
- Risk of hyperkalaemia due to potassium retention (rarely and especially in patients with renal dysfunction)
- Angioedema of the face, extremities, lips, tongue, glottis, and larynx has been reported in patients treated with ACE inhibitors including Benazepril (rare but potentially fatal). Black patients receiving ACE inhibitors have been reported to have a higher incidence of angioedema compared to nonblacks.
 RELATED LINKS
|ACE inhibitors||Benazepril (Lotensin) • Captopril (Capoten) • Cilazapril • Delapril • Enalapril (Renitec, Vasotec) • Fosinopril (Monopril) • Lisinopril (Prinivil, Zestril) • Moexipril (Univasc) • Perindopril (Aceon) • Quinapril (Accupril) • Ramipril (Altace, Triatec) • Trandolapril (Mavik) • Zofenopril (Bifril, Zopranol)|
|Angiotensin II receptor antagonist||Azilsartan (Edarbi) • Candesartan (Atacand) • Eprosartan (Teveten) • Irbesartan (Aprovel, Avapro, Karvea) • Losartan (Cozaar) • Olmesartan (Benicar, Olmetec) • Telmisartan (Micadis) • Valsartan (Diovan, Tareg)|
|Renin inhibitors||Aliskiren (Rasilez, Tekturna)|
|Alpha-1 blockers||Doxazosin (Cardura) • Prazosin (Minipress) • Terazosin (Hytrin)|
|Alpha-2 agonists (centrally acting)||Clonidine (Oral route) • Clonidine (Transdermal) (Catapresan) • Guanfacine (Tenex) • Methyldopa (Aldomet)|
|Calcium channel blockers||Dihydropyridines||Amlodipine (Norvasc) • Barnidipine (Vasexten) • Felodipine (Plendil) • Isradipine (Dynacirc) • Lacidipine (Lacipil, Motens) • Lercanidipine (Zanidip) • Manidipine • Nicardipine • Nifedipine (Adalat) • Nisoldipine • Nitrendipine|
|Benzothiazepine||Diltiazem (Cardizem, Taztia XT, Tiazac, Tildiem)|
|Phenylalkylamine||Gallopamil • Verapamil (Calan)|
|Beta blockers||Beta1 selective (cardioselective)||Acebutolol (Sectral) • Atenolol (Tenormin) • Betaxolol (Kerlon) • Bisoprolol (Concor) • Celiprolol (Cordiax) • Metoprolol (Betaloc, Lopressor, Toprol-XL) • Nebivolol (Bystolic, Lobivon, Nebilox)|
|Nonselective (Beta1 and Beta2 blockers)||Oxprenolol (Trasitensin) • Propranolol (Inderal) • Timolol (Blocadren)|
|Nonselective (Beta1, Beta2 and Alpha1 blockers)||Carvedilol (Dilatrend) • Labetalol (Trandate)|
|Beta blocker with intrinsic sympathomimetic activity (ISA)||Acebutolol (Sectral) • Celiprolol (Cordiax)|
|Lipophilic Beta blockers||Propranolol (Inderal) • Metoprolol (Betaloc, Lopressor, Toprol-XL) • Oxprenolol (Trasitensin)|
|Diuretics||Carbonic anhydrase inhibitors||Acetazolamide (Diamox)|
|Loop diuretics||Bumetanide • Etacrynic acid • Furosemide (Lasix) • Piretanide • Torasemide (Demadex)|
|Thiazide diuretics||Chlorothiazide (Diuril) • Hydrochlorothiazide (Esidrex)|
|Thiazide-like diuretics||Chlortalidone (Hygroton) • Indapamide (Lozol, Lozide) • Metolazone|
|Potassium-sparing diuretics|| Epithelial sodium channel blockers: Amiloride (Midamor) • Triamterene (Dyrenium) |
Aldosterone receptor antagonists: Potassium canrenoate • Eplerenone (Inspra) • Spironolactone (Aldactone)
|Combination therapy||Amiloride/Hydrochlorothiazide (Moduretic) • Spironolactone/Hydrochlorothiazide (Aldactazide)|